This invention relates to a new, improved, and economical device for the neutralization of alkaline wastes from the carbonated beverage industry using inexpensive carbon dioxide in a non-pressure vessel.
Carbonated beverage plants are the largest users of carbon dioxide gas and, therefore, have available large volumes of this gas at costs well below that of other mineral acids such as sulfuric acid. They also must use alkaline cleaners in aqueous solution to clean the bottles or other beverage containers.
It has been conventional to discharge the alkaline waste waters into a municipal sewage system or even into a convenient body of water because the primary pollutant is only alkali resulting in a pH which varies from about 8.0 to perhaps a maximum of 13.0. One characteristic of such waste flows is that they are almost never equalized so that over a short period of time, the degree of alkalinity may vary widely.
As public concern with degrees of pollution has increased, various federal, state and local regulatory bodies have enforced definite limits as to the kind and amount of pollutants permitted in any given waste effluent. Insofar as the carbonated beverage bottling industry is concerned, the major pollutant is alkali discharged from container cleaning operations, so that a system for neutralizing the excess alkali is the major waste treatment needed.
Any acid reacting material might be used to adjust pH to any given point, but the use of carbon dioxide which, for the most part, is the cheapest acid available to the carbonated beverage industry, must be utilized under very special and efficient conditions before it can be competitive with the usual sulfuric acid systems.
It is therefore an object of this invention to provide a system for treating an alkaline waste water so as to bring the pH down to a given quality standard, thus permitting its discharge into public facilities.
It is another object of this invention to utilize carbon dioxide as the neutralizing acidic material. Still another object of the invention is to use the carbon dioxide in such an efficient system that it is the most economical acid reacting material available to the carbonated beverage industry.
It is a further object of this invention to effect this neutralization without using a closed reaction zone under pressure.
These and other objects of this invention will become apparent from the following description and claims appended thereto.